tan(兀/2-A)=1/tan
证明:(1+tan a+cot a)/(1+tan^2 a+tan a)-cot a/(1+ tan^2 a)=sin
tan A:tan B:tan C=1:2:3 求A:B:C
证明,tan(A/2)-1/tan(A/2)=-2/tana
tan(a+b)=3,tan(a-b)=1/2,求sin2a/sin2b
已知tana=1/7,tanβ=1/3,求tan(a+2β)
2(tan a+tan b)
(cot (a/2) -tan (a/2))^2(1-tan a / tan (2a))
已知tan(A-B/2)=2,tan(B-A/2)=-3 求:(1) tan[(A+B)/2] (2) tan(A+B)
若tan(A+B)=2/5,tan(A-π/4)=1/4,则tan(B+π/4)等于多少?
为什么 tan a +1/tan a=sin^2 a +cos^2 a/(sina cos a)
tan(a-3/π) =2 tan(3/π-B)=2/5 求tan(a+b)=
cosa=cosb*cosr求证tan(a+b)*tan(a-b)=tan^2(r/2)